This invention is directed to adjustably mounting an inner housing within an outer housing of a movie camera and, in particular, to adjustable mountings that selectively and adjustably mount an inner housing within an outer housing in a movie camera for dampening sound produced within the outer housing and permitting adjustment of the positioning of the inner housing in at least three perpendicular directions.
Over the years, different proposals have been made for modifying motion picture cameras of the professional type that are used for producing motion pictures that have sound tracks in an endeavor to reduce the sound generated by the mechanical components of the movie camera. Specifically, in producing motion pictures it is essential that the camera used for such work produce as little sound as possible in order to avoid recording on the sound track unwanted sounds produced by the mechanisms within the motion picture camera. Because most efforts to create less noise have been less than completely satisfactory, for many years it was customary to provide a "blimp" to enclose the motion picture camera and, thus, minimize unwanted sounds produced by the camera. However, the blimp was found to be awkward and cumbersome and could not be readily used unless the camera was mounted on a tripod.
In recent years, however, efforts have been made to provide a portable, lightweight motion picture camera which can be hand-held or balanced on a shoulder and reduces the sound to a level whereby a blimp can be avoided. Such efforts are disclosed in U.S. Pat. Nos. 4,082,436, 4,101,916 and 4,121,886 assigned to Panavision Incorporated, wherein an effort is made to position those mechanisms that generate the most sound on a support plate positioned entirely within the outer housing of the camera and to utilize resilient damping elements for mounting the support plate to the outer housing so that much of the sound generated by the inner housing is damped by the resilient supporting elements. The use of resilient sound damping elements for supporting an inner housing within an outer housing is also disclosed in U.S. Pat. No. 4,013,352.
Although the use of resilient sound damping mounting elements can reduce the noise generated by the camera, it has been found that such mounting elements do not take into account the adjustability of the inner housing of the movie camera with respect to the outer housing of the movie camera and the effect that such adjustability has on the camera optics. Furthermore, the use of sound damping elements in and of themselves, may cause unwanted oscillational displacement or repositioning of the inner housing with respect to the outer housing as the resilient sound dampening material becomes fatigued.
The photographic optics (lenses) of the camera are, as a rule, mounted to the outer housing of the camera and utilize different types of lens and camera mountings to permit the optics to be interchangeable. The mounting most commonly used for 35 mm movie camera is the BNCR mounting. The critical aspect of interchangeable mountings is the focal plane distance and the variation of same as the photographic optics are changed on the camera. Specifically, the focal plane distance, namely, the distance from the support surface of the adaptable fittings of the photographic optics to the plane of the film and the film gate is the factor that is most significant in obtaining a correct focusing of the lens. All photographic optics with a BNCR adjustable fitting must be able to fit on all cameras with a BNCR mounting and must admit of equal focusing no matter what lens or mounting is utilized.
As a practical matter, problems with focusing often arise when lenses of one manufacturer are utilized with a camera by a different manufacturer. Also, focusing problems exist when zoom lenses are to be utilized because the focal distance of the lens during zooming causes the optical center of the image to shift. This shift is caused by the center axis of the interchangeable fittings of the zoom lens not corresponding with the center axis of the film gate. For example, there can be discrepancies between the distance, the vertical and/or the horizontal positioning of the film gate and the optical axis. Such shifting is often caused by the lack of an optimum fit between the optics and the camera mounting as a result of wear on the camera and often results in the film gate being inclined with respect to the optical axis.
Heretofore, efforts to dampen the noise created within the camera housing have not taken into account the adjustment of the focal plane of the camera housing and, hence, have been less than completely satisfactory. Similarly, efforts to assure adjustment of the focal plane of the camera have not taken into account noise dampening of the type that is contemplaed by the instant invention. Accordingly, an adjustable mounting for use with an inner housing having noise producing mechanisms of the camera supported thereon and that dampen the noise transmitted to the outer housing and permits adjustment of the inner housing with respect to the outer housing to optimize focusing thereof is desired.